Diameter changes in rabbit aorta during fixation at physiological pressure

Quantitative Measurement of Fixation Rate and Dimension Changes in the Aldehyde/Pressure-Fixed Canine Carotid Artery

“…When the luminal surfaces of immersionfixed vessels are viewed by scanning electron microscopy, protrusions, wrinkles and cyto plasmic bridges are seen [8,9]. When the rabbit aorta is fixed at physiologic pressure, Tindal and Svendsen [10,11] report that some surface wrinkling is retained. Several other reports [12][13][14] state that rabbit aortae and other arteries fixed at above diastolic pressure have a smooth surface with only slightly bulging endothelial cell nuclei.…”

“…Tindall and Svendsen [11] reported a sig nificant increase (approximately 20% by our calculation) in the diameter of the rabbit aorta during perfusion of fixative from a constant pressure reservoir. By contrast, Weiner et al [17] measured a 35% decrease in pig coronary artery lumen diameter when the in vivo diameters before the beginning of perfusion fixation were compared to those after completion of fixation.…”

Some Characteristics of Intimal Folds in the Rabbit Aorta

“…It was shown that the internal elastic membrane was too large to fit into the blood vessel wall unless it was corrugated. Furthermore Tin dall and Svendsen [1984] demonstrated that rabbit aor tas fixed at physiological pressure dilated beyond the in vivo dimension which explains the lack of folds observed after pressure fixation [Clark and Glagov, 1976;Davies and Bowyer, 1975;Swinehart et al, 1976], The present study was undertaken to answer the fol lowing question: if the intimal folds and their pattern in the fresh relaxed aorta are eliminated by tangential ten sion, do folds reappear haphazardly on relaxation, or do the very same folds reappear?…”